Polyethylene comopositions containing 2, 4, 4&#39;-trihydroxybenzophenone



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POLYETHYLENE COMPOSITIONS CONTAINING Z,4',4'-TRIHYDROXYBENZOPHENONE Gordon C. Newland,lJohn W. Tamblyn, and Charles J.

Kibleiy'Kingsport, Tenn., ,as signors to Eastman Kodak ldnlpa y, .kochest rl N-ii-la corporation, o

ion relates tolthe; abili' en and more. p f pul r a, polyethylene compositionfag'ains't, g. from exposure to, 's'unlight o1:,nlt

inhibitors, are, known, whiphQare; ,llSeCl enora ion r I degradation 'i of ma y, pl

- 7 t'e'rialsl "However,"'s oln'e' of thef mosteffective of these yethylene is subject to d,e1;erio'ra tionw when'ex sed' to ultraviolet light; ,A number, ofs'o -callecllultrav olet Y inhibit; thefde- ,r or rem-Lula? corp ated'or blended inYpolyethylenecompositions by United seesaraem methoc'l disclosed for Fawcett et al. insU.S. Patent 2,153,- 553, High-density polyethylene usually has a density of about 0.94 to 0.97 and can be prepared by such methods as are disclosed-in -co-pending applications of 'Coover, US. Serial No. 559,536 which wasrfiledllan 'uary' 17, 1956, and US. Serial No. 613,609 which was s filed ct'ober 3,l-- l 956. ..-The. "subiect stabilizer: canine used as ult'rlaviol'et inhibitors .fforl conventionalfpolyefhylf known ultraviolet inhibitors f orl such plasticmaterials as.

such; ultraviolet inhibitors, ga e; 2, 4 dhyd i'ry none and "2,2,4, lFtetrahydroxybenaophenon u e e Q 'h i e mqn l't ii fii i w t p ibleyvith, bu t are 'no't 'entire1y' satisfactor rs fir r i t yl nei l d q i i i' e bili 'zersffor; h51pg p ta m ljirners "su y khlr d z l yin l i e i. ,ch bi ei'a d' h not i1'elacessa rily elfe'ctiveistabilizer s in, polyeth stab j ls rs *ingjha lo n -containing polymers func P elthy lenegdo not serve this "functioni :Hence, it Fis'lhighly unpredictableas'to whether-a given stabiliz erf or'ultraviolet inhibitor will becompatible with, and a good-stabilizer for, polyethylene compositions short o ffactually testingthe material in polyethylene.

' It is an object Of-thlS'lIlYIltlOIl to provide newpolye 3 ene compositions as w The-i b iolet- Lo fthe invention} ,canbe -in- 4.9 ih n eut nal m hods sed orz l n ingisuch materials; into resins; orgplastics. Typical :of; such; meth- ,odsl that can-be suitably employeddnclu'de milling on I heated rolls, deposition frorngsolvents and dry-blending.

ethylene compositions of high stability against deterioration resultingfrom exposure, to sunlight or-ultraviolet light.

' "It is a further object of this invention top'ro'vide novel polyethylene compositions containing an additiv'ef that is coinpatible with, and an effective "ultraviolet inhibitor f or thje polyethylen e'compositions; a I 7 t s... e ,a jO iw f h in n iq i to; pr v e nov l ql e hyl nem o ons Q ainin a y oxybenzophenone ultravioletifinhibitor that will not? exude therefrom. l

'Other:objects of.theinveritionwill.bel-apparentffrom V 7 t Into polyethylene having a molecular weight of about v dfja density of 0.945 was hot-roll-compounded' 1% y weightof 2,4,4-trihydroxybenzophenone. The

the'description and rclaim's whi ch follows. i

- P i ns 9 i p oved: es s anqei rde e o at on d e. 1

1 a The ultraviolet inhibitor "ofthepresentinvention;

'ihydro xybenzophenone, lends ,to polyethylene V corn s1 ns improved stability, and more specifically imtability against deterioration resulting from exytowsunlight or ultraviolet light. 7 Also, the subject 7 inhibitordoes;-not---impart objectionable discolorationto l V vpp yet hylene. Thus, polyethylene cornpositionsstabilhed in ccordance withdihefinvention can be for a Wie' 'd Yer t'Y-pfi ap l a ns p eth en a-. l l zq i ithe inv nt 'o apart romeinga an k fle tive stabilizer against deterioration resultingfrom'n'exposure, i to ultraviolet light, hasjj unexpected compatibility with polyethylene compositions; Forexample, while the subi' slt -2,-4 '1- f ihy o y enzop non has go d c mpatibile;

ity with polyethylene -co1npositions, such closely related compounds as l 2,4'-dihydroxybenzophenone and 2,-27 ,4,4

tetrahyglr'oxybenzophenone are not compatible withpolyethylene compositions. The-former exudes from poly t deterioration in polyethylene .is illustrated by'the ren w;

ethylene after being compounded therein while the -lattr -i's' insoluble in polyethylene. Y

The eflective ness 0f 2,4,4-trihydroxybenzophenone as a;st ab'ilizer, agaihstpliotodegradation or ultraviolet light ing examples of typical polyethylene stabilizertests;

ultraviolet r 'ght having inconzorated:t ereinrax i hi a ng I amount ot;52,4,4?ftrihydroxybenzqphenone' Whichi'has the following structuralfforrfiula: .1 -i

n The subject' ulltirayiolet in bito' bilize awide variety 'of e y e hy .,..C9n .n a a polyethylene, usually has a" density offabout 0 and can be prepared by several Inethi mclud iPlhF'Sf di ed u Qf iq qm r s l -m d he :bent" 'ntolazfl-shape'i, and: exposed-rte outdoor weathering;

EXAMPL 1 resulting composition was'thereafter 'compression mold'ed into sheets about 1 inchthick. Ten samples, l /uby' atzaKingsport, Tennessee; ;-The stressed; portion iof each sample was mounted facing south. Ten additional sam a ,ples were preparedcontainingv no stabilizer and were v;- alscafisubjectetl to;theiiweathering,testgfor"comparative Y Pu po V th' "first sample, 1half thesarnples (five'samplesfland ll sanipliesiare recorded below in Tablel for both iThe exposure times in days f requiredi to craclc le's" containing 2,4,4!-trihydroxybenaophenone esaniplesfontaining no stabilizerfT I well as, thelso-called;polyethylene V 3 Table] Stress-Cracking Resistance Exposure Times in Days Required to Craek Stabilizer 1 Sample Samples Samples none 160 170 330 2,4,4-Trihydr0xybenzophenone 390 400 450 Into polyethylene having a molecular weightof about 1 27,600 and a density of 0.919 was hot-roll-compounded 1% by weight of 2,4,4-trihydroxybenzophenone.. The resulting composition was thereafter compression-molded into sheets l s inch thick. Ten samples of thercsulting sheets were prepared and subjected .to the outdoor weathering test as described in Example 1. Ten samples containing no stabilizer were also included in the weathering test. In Table 2 below is recorded the number of days exposure required to produce cracks in half ofthe samples (five samples).

Table 2 Stress-Cracking Resistance Exposure Time in Days Required to Crack Half the Samples Stabilizer 170 2,4,4-lrihydroxybenzophenone V None of the 2,4,4-dihydroxybenzophenoneexuded from the polyethylene samples during the course of the weathering test.

EXAMPLE 3 per minute. The results of the test are summarized by the data in Table 3 below.

Table 3 Percent original Stabilizer Elongation Retained After 14% Months Exposure none 10 2,4,4'-trihydroxybenzophenone 30 None of the 2,4,4'-trihydroxybenzophenone exuded from the polyethylene during the course of the weathering and elongation tests. r

' EXAMPLE 4 7 The subject stabilizer, 2,4,4-trihydroxybenzophenone,

has good compatibility with polyethylene, which com patibility many closely related compounds do not possess.

Several stabilizers at a level of 1% by weight were incorporated in polyethylene by milling on heated rolls, compression-molded into 60 sheets of polyethylene,

and exposed to outdoor weathering as described in Example 3. After 14 /2 months of weathering, the surfaces of the respective samples were examined for possible exudation of the stabilizer additive. Table 4 below summarizes the results of the compatibility test of several hydroxybenzophenoncs in the polyethylene samples.

Table 4 Amount of Stabilizer Exuded Stabilizer Additive none none. 2,4,4-Trihydr0xybenzophenone none. 2,4-Dihydroxybenzophen0ne.. much. 2,2-Dihydroxy-44-dimethoxybenzophenone much. 2,4-Dihydroxy-5-hexylbenzopl enone much. 2-Hydroxy-4,4-dimethoxybenzophenone much.

The hydroxybenzophenone, 2,2'4,4'-tetrahydroxybenzophenone, was found to be insoluble in the polyethylene at a 1% level and could not be incorporated therein. As can be observed from the information set out in Table 4, 2,4,4-trihydroxybenzophenone has good compatibility in polyethylene, which compatibility other" closely related hydroxybenzophenones do not, possess. The, 2,4,4-trihydroxy benzophenone stabilizer of the invention c'an be prepared by the method described in Example S below.

" EXAMPLE 5 acid, 22.0 g. (0.2 mole) of resorcinol and 200 ml; of tetrachloroethane was placed in a 500 ml. flask equipped with a stirrer, a' gas inlet tube, and anair condenser. Boron wtrifluoride gas was introduced into theflask with constant stirringuntil 20.0 g. had been absorbed, 3 hours being required. The resulting mixture was then heated with stirring ona steam bath for 4 hours. The reaction mixture was thereafter cooled to room temperature and added toa solution of 55 g. of sodiurn acetate in 300 ml. of .water. The resulting yellow crystallinesolid was filtered, dissolved in 10% sodium hydroxide, reprecipitatedwith dilute hydrochloric acid, filtered, washed with dilute sodium bicarbonate solution; and then recrystallized from a 1:1 methanol-water solution. We obtained 33 g. of product which was recrystallized from ml. of nitrobenzene to obtain 28.6 g. of yellow crystals melting at 20020l.5 C. The empirical formula of 2,4,4- trihydroxybenzophenone is C H O the carbon and hydrogen content being C=67.82% and H=4.35%. The present product was found to contain C=67.6% and H=4.39%. 1 7

Although the invention has been described 'in considerable detail with reference to certain preferred embodiments thereof, it will be understood that variations and modifications can be efiected within the. spirit and scope of the invention-as described hereinabove and as defined in the appended claims.

We claim: I

1. A polyethylenecomposition containing dispersed therein 0.1% to 10% by weight of 2,4 ,4'-trihydroxybenzophenone as an agent to inhibit deterioration of said polyethylene composition by ultraviolet light. I

2. A polyethylene composition containing dispersed therein 0.5%to 5% by weight of 2,4,4'-trihydroxybenzophenone as an agent to inhibit'deterioration of said polyethylene composition by ultraviolet light.

3. A polyethylene. composition containing dispersed therein about 1% by weight of 2,4,4-trihydroxybenzophenone as anagent to'inhibit deterioration of said polyethylene composition by ult raviolet light.

References .Qited in the file of this patent,

- Knowles etlali: 'J'."Am.;-Oil .Chemists Soc.,;32, 158 160 (1955); (Copy in Div. 63.)

.:U C and E News, Oct. 14,1957, page 131.

(c y iaL b al'y-l I.

A mixture of 55.2 g. (0.4 moles) of p-hydroxybenzoic 

1. A POLYETHYLENE COMPOSITION CONTAINING DISPERSED THEREIN 0.1% TO 10 BY WEIGHT OF 2,4,4-TRIHYDROXYBENZOPHENONE AS AN AGENT TO INHIBIT DETERIORATION OF SAID POLYETYLENE COMPOSITION BY ULTRAVIOLET LIGHT. 